8
INSTALLATION AND MAINTENANCE
LSA 49.1 4P
ALTERNATORS
INSTALLATION
3007 en - 11.2004 / e
LEROY-SOMER
3 - INSTALLATION
3.1 - Assembly
All mechanical handling operations must be undertaken
using approved equipment.
Whilst being handled, the machine should remain
horizontal.
3.1.1 - Handling
The generously-sized lifting rings are for handling the
alternator alone. They must not be used to lift the genset.
Choose a lifting system which respects the positioning of the
rings.
3.1.2 - Coupling
3.1.2.1 - single bearing alternator
Before coupling the two machines, check that both are
compatible by :
- undertaking a torsional analysis of the transmission on both
units
- checking the dimensions of the flywheel and its housing, the
flange, coupling discs and offset
When coupling the alternator to the prime mover, the
holes of the coupling discs should be aligned with the
flywheel holes by rotating the primary pulley on the
thermal engine.
Do not use the alternator fan to turn the rotor.
3.1.2.2 - Two-bearing alternator
- Semi-flexible coupling
Careful alignment of the machines is recommended,
checking that the concentricity and parallelism of both parts
of the coupling do not exceed 0.1 mm.
This alternator has been balanced with a 1/2 key.
3.1.3 - Location
Ensure that the ambient temperature in the room where the
alternator is placed cannot exceed 40°C for standard power
ratings (for temperatures > 40°C, apply a derating
coefficient). Fresh air, free from damp and dust, must be able
to circulate freely around the air intake grilles on the opposite
side from the coupling. It is essential to prevent not only the
recycling of hot air from the machine or engine, but also
exhaust fumes.
3.2 - Inspection prior to first use
3.2.1 - Electrical checks
Under no circumstances should an alternator, new or
otherwise, be operated if the insulation is less than 1
megohm for the stator and 100,000 ohms for the other
windings.
There are three possible methods for restoring these
minimum values.
a) Dry out the machine for 24 hours in a drying oven at a
temperature of approximately 110°C (without the AVR).
b) Blow hot air into the air intake, having made sure that the
machine is rotating with the exciter field disconnected.
c) Run in short-circuit mode (disconnect the AVR) .
- With the machine stopped, short-circuit the three output
power terminals using connections capable of supporting the
rated current (try not to exceed 6 A/mm2).
- Insert a clamp ammeter to monitor the current passing
through the short-circuit connections.
- Connect a 12 Volt battery to the exciter field terminals,
respecting the polarity, in series with a rheostat for adjusting
the resistance in order to obtain an excitation current equal to
the rated stator current (eg : 10Ω/50W),
- Open fully all the alternator openings.
- Run the alternator at its rated speed, and adjust the exciter
field current using the rheostat to obtain the rated output
current in the short-circuit connections.
Note : Prolonged standstill : In order to avoid these problems,
we recommend the use of space heaters, as well as turning
over the machine from time to time. Space heaters are only
really effective if they are working continuously while the
machine is stopped.
WARNING
WARNING
